The present study will experimentally compare the relative effectiveness of three different intervention approaches in the treatment of 150 Hispanic children with functional disorders. These three service delivery models are referred to as "Conjoint Family Therapy," "Multiple Family Therapy," and "Family Therapy with One Person." All three experimental treatment conditions will be conceptualized along the tenets of Brief Strategic Family Therapy, a family systems theory. Brief Strategic Family Therapy is a family systems oriented theory in which the entire therapy process is completed within 12 sessions and in which intervention strategies are carefully planned so as to bring about a rapid reorganization of maladaptive family interaction patterns and reduction of symptomatic behavior. The three experimental treatment conditions will be rigorously compared with respect to treatment effectiveness. Treatment outcome will be evaluated by reduction in problem behaviors as measured by the Behavior Problem Checklist, psychiatric impairment as measured by the Screening Inventory for Psychiatric Impairment, disparity between family ideal and real environment scores as measured by the Family Environment Scale, and presenting complaint symptomatology. Treatment outcome will also be measured by improvement in the perception of actual family environment as measured by The Family Environment Scale, and in general ecological functioning as measured by the Ecological Functioning Ratings. The relationship of level of acculturation to treatment effectiveness will also be assessed.